Structural characterization of porous low-k thin films prepared by different techniques using x-ray porosimetry

X-ray porosimetry (XRP) was used to characterize three different types of porous low-k dielectric films, with similar dielectric constant. It was demonstrated that XRP can perceive subtle differences in the pore structures of similar low-k films. It was shown that the porous SiCOH film displays the smallest pore sizes, while porous hydrogensilsesquioxane (HSQ) film has both the highest density wall material and porosity. The results show that porous methylsilsesquioxane (MSQ) film exhibited a broad range of pores with the largest average pore size.